There is no substitute for a live training partner, but sometimes a training partner just isn't available and drilling is an important part of training for groundwork grappling.
For those times I don't have a training partner available and want to train/drill grappling technique and ground work how useful would a grappling dummy be?

The closer to a live person a dummy is, the more useful I would expect training with them to be. How close to a live person are they?

Can you put them into different positions and expect them to be able to maintain those positions given no outside interference? Eg If a dummy is put into a kneeling position, can it hold that position without toppling?

When you attack a joint, how much resistance is there? Eg If you try to armbar a dummy, will you feel no resistance at first, then resistance when the arm is straightened out at 180 degrees, or will you feel progressive and increasing resistance leading up to the straightening of the arm, or will you feel no resistance even past 180 degrees?

How lifelike are the joints? Eg are the elbows hinge joints, do the shoulders simulate the ball and socket joints of a human shoulder?

Of course the dummy would be unable to react respond to your movements.

Extra points for those who have tried multiple dummies, and both commercially available dummies and home made dummies.

Never used one, but i've read that they are actually -better- than a training partner, when used in conjunction. This is because you do not have to "water down" techniques by altering them so the uke can safely ukemi out of it. I'm very curious to see what people have to say.
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ChrisApr 4 '12 at 3:59

1

There have been some decent answers. However I'm looking for an answer from someone with at least a moderate amount of time training with them, or an answer that references the experiences of others.
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chobokMay 25 '12 at 6:37

training dummies are great.. I can even cope when the gym names their dummy "Brian'.. it's difficult to cope when people say they're going to visit "Brian" ;)
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user1414Oct 22 '13 at 13:34

4 Answers
4

Grappling dummies are most useful for a ground work not for take down training.

From what is available on the market submission master is most realistic grappling dummies available Part of what makes it so good is the fact that its arms and legs are stiff enough to be realistic and also to return back to their original position, but also elastic enough to easily bend into the various submissions. I found this site useful for grappling dummy info.

Disclaimer: I can add up the number of minutes I've personally spent with grappling dummies without taking off my shoes. (And by "grappling dummies" I don't mean "judoka who've had too many concussions".)

If you're fairly new to grappling I would stress that it IN NO WAY is a substitute for training with real partners and that you'll still need to do that all the time.

...and some answers to specific questions:

Q: Can you put them into different positions and expect them to be able to maintain those positions given no outside interference?

A: It depends:

You can probably imagine basically which moves it's possible to do with a dummy, but here's an extended take. Standing guard passes work really well, as you can basically bend the limbs out to mimic somebody spider-guarding you - although obviously you won't get the same pressure. Moves from mount and side mount are great. Leglocks (I've been working on some stuff from Reilly Bodycomb which are against BJJ rules) work great. Submissions from guard are more tricky, because it's difficult to get the right pressure from the dummy - but I've been practicing some rubber guard stuff with reasonable success. Sweeps from guard are tough, because you can't really get the dummy to posture up on its knees properly without tying its legs together. Guard breaks aren't that useful, although you can simulate a closed guard/halfguard by tying its legs together. Escapes from mount and sidemount aren't the best because you aren't getting proper pressure from your opponent. Moves that require the dummy to be on hands and knees (stuff from sprawl control, say) require you to tie the dummy's legs together. Anything with you on the ground and the dummy standing clearly won't work. A general rule of thumb is, if you need to 'feel' an opponent's pressure or balance to make a move work, you aren't going to be able to drill it properly with the dummy. The website claims that you can practice throws on it, but that seems ridiculous. That still gives you a lot to work on, though.

I am surprised and a bit dubious that he doesn't see the benefit of practicing throws on an object that doesn't whine when you makikomi (land on it). Perhaps that's more useful for people who already understand the mechanics and pressures of a throw and just need to ingrain the total commitment necessary to throw hard.

Q: When you attack a joint, how much resistance is there?

A: It's not meant to mimic a human's resistance, it's meant to mimic a body's mass. So, no, it won't try to stop your armlock and then have the same amount of tension at the elbow joint. From a related /r/bjj post, this time regarding a homemade dummy:

[He] comfortably bends his joints at all the same angles as we do.

If you try and force it at points where the natural tap "zone" would be you meet resistance. The wiring is electrical service entrance wiring as well so provides stiffer resistance when you go against the natural curvature of Bubba the majority of the time.

Q: How lifelike are the joints?

A: If you take a look at the pictures of this homemade dummy, obviously the answer is "not terribly". The answer above suggests that commercial dummies are better, but I wouldn't expect much. These are more "punching bags with limbs" than crash-test dummies. Again, we're replicating the mass of the body, not its actual physiology.

But I'm not sure that's the point. As the homemade-dummy-maker explains, the purpose of the dummy is to drill copiously, or drill when no partners are around, not to perfectly mimic the feel of a real human:

How much use this dummy is going to be to you is down to two things: how convenient it is, and how dedicated you are. I've got a girlfriend who lets me leave it in the living room for days on end and at worst put it in a cupboard, and as such it's always there - if I had to go train in the garage with it, or wait until I was alone in the house, it wouldn't be as useful. As it is, it's like having a training partner who never demands a go, or says he's tired, or doesn't fancy training. If you want to do a move 100 times you can. If you're reading an instructional at midnight and need someone to try the move on, it's there. If you've got ten minutes before breakfast, you can bang out some reps of that move you're going to try in the evening. I can't emphasise enough how useful this is.

But that wouldn't work without discipline. I enjoy jits, but more than anything I enjoy feeling like I'm getting better at it, and going from class to class without a structured way to improve was getting to me. Training with the dummy is boring, but if you've got the discipline to do those 100 reps, it will get you results. Look at it this way: if you're the sort of guy that ends up chatting to your partner during the drilling bit of class, you might not get much out of it. I'm a big believer in Eddie Bravo's idea that doing a move should be as instinctive as tying your shoes, and if you do enough reps, it will be.

Grappling dummies have their place and are useful. But like you said they are no substitute for a real body.

I must preface this with the fact that they only grappling dummies I've used are the ones with no legs or arms that are really only mean for dragging around, picking up, and working ground and pound. and they are good for that.

As for grappling dummies for practicing throws: I would say your better of doing uchi komis to work on your foot work, body movement and breaking the balance, once you've got that, no grappling dummy will react the same as a human body for the actual throw part so it won't be that beneficial. Better off wrapping a gi around a pole.

Dummies (with limbs) are a great tool to build proprioception, specifically around maneuvering across and around body-shaped objects (like a body). They build awareness of possible limb positions and help drill the "baseline" moves used in grappling.

Your specific questions are unanswerable, because there a wide variety of dummies available.

Heavier ones can be used as part of a strength and conditioning program and can help figure out your own idiosyncrasies regarding throws, pivot points, and so on--obviously a dummy won't react like a person, but that isn't always the point: when you're learning a technique, particularly ones drill able from a static(-ish) starting point, your opponent isn't going to defend either.